Chair



Patented Dec. 13, 1927.

PATENT OFFICE.

ANDREW J'. CRAVEN', 0F BROOKLYN, NEW YORK.

CHAIR.

Application filed March 5, 1925. Serial No. 13,012.

This invention relates to chairs, and more particularly to chairs of that type usually provided for use by stenographers and typists, which are primarily characterized by the fact that such chairs have a back adjust ably mounted upon a supporting frame ar ranged for tilting or pivotal movement upon the spider or iron to which the seat is fixed.

One of the important objects of my presio ent improvements is to provide a construction wherein the seat iron and the back supporting frame are each in the form of a single one piece casting whereby the production cost of chairs of this type is appreciably reduced.

It is another object of my invention to provide an improved means for pivotally connecting the back supporting frame with the seat iron or spider whereby, after a seat has been secured upon the arms of the spider,

the possibility of separation or detachment of the parts is etfectually prevented.

My invention also provides for an improved arrangement of the coil springs surrounding oppositely extending arms of the seat iron, the extremities of said springs being respectively extended forwardly and rearwardly and the forward ends thereof engaged with suitable lugs on one of the arms of the seat iron, and said back supporting frame being provided with suitable seats to receive the rear ends of said springs.

It is also an additional object of my invention to provide improved means for adjustably positioning the back upon the rear end of the pivotally mounted frame whereby said back may be readily disposed in various vertically inclined positions and without necessitating the manipulation or adjust-ment of clamping nuts, screws or other quently incorporated in the subjoined claims.

In the drawings, wherein I have illustrated one practical and satisfactory embodiment of my present improvements, and in which similar reference characters designate corresponding parts throughout the several views,

Figure 1 is a side elevation partly in section illustrating a stenographers or typists chair constructed in accordance with my present invention;

Fig. 2 is a horizontal sectional view taken on the line 2 2 of Fig. 1;

Fig. 3 is a detail vertical section taken on the line 3 3 of Fig. 1;

Fig. 4. is an enlarged detail section taken on the line 4- 1 of Fig. 2, and illustrating .two different positions of the back supporting framein broken lines;

Fig. 5 is a detail sectional view taken on the line 5 5 of Fig. 1, and

Fig. 6 is a detail front elevation of the ad]ustable back rest plate and the upper end portion of the `chair back. Referring in detail to the drawings, 5 des ignates a hollow pedestal or bolster preferably provided with the external flattened surfaces indicated at 6 against which the upper ends of the radially disposed chair legs 7 are securely fixed in any approved manner. This pedestal 5 loosely receives the post or standard 8 which is provided with the usual coarse thread 9. Upon the upper end of this post 8 the seat supporting spider or'iron 10 is suitably secured. This spider is in the form of a one piece casting having a relatively long forwardly extending arm 11 and `a comparatively short rearwardly extending arm 12, the extremities of said arms being upwardly bent or offset as clearly shown in Fig. 1 of the drawings. Similar arms 13l of equal lengt-h also extend at right angles to the arms 11 and 12 and theA oiset end of each arm terminates in an apertured ear 14 upon which the under side of the seat 15 is engaged and to which said seat is rigidly secured by means of suitable screws 16. Further reference will be hereinafter made to this seat supporting spider.

.The upper end of the bolster 5 is provided with a ange 17 and between this flange and the collar 18 a suitable ball bearing 19 is interposed. The collar 18 is provided with a, key 20 engaged in the longitudinally extending key-way 21 formed in the threaded post 8.

A .nut 22 rests upon the collar 18 and is provided with a coarse split thread engaged with the thread of the post 8. By providing such a split thread, the nut may be produced in the form of a casting, no machine work being required in order to assure a. roper engagement of said split thread with the thread of the post. This nut is provided et its upper end with an outwardly and downwardly curved flange 23 which provides a convenient handgrip whereby said nut may be turned. At its lower end the nut is also formed with an outwardly projecting annular flange 24 and aA stud or pin 25 fixed in an upwardly extending ear 26 on the bolster flange 17 overlies this flange 24. Thus, it will be apparent that when the nut 22 is rotated, the post 8 is moved vertically in the bolster to raise or lower the seat 15 to the desired height.

The back of the chair is adjustably mounted upon a frame 27. This frame is in the form of a substantially U-shaped casting having its intermediate portion ext-ending rearwardly of the seat and the spaced arms thereof projecting forwardly beneath said seat. Each of these fra-me arms 28 is provided at its forward end with a transversely projecting pivot lug 29. These pivot lugs are adapted for engagement respectively in recesses or seats formed in upwardly projecting ears 3l on the transversely extending arms 13 of the seat iron or spider. The recesses 30 are open at their front sides and provide entrances 32 for the lugs 29 as indicated in Fig. 4 of the drawings, wherein it will be noted that these entrances to the recesses are of appreciably less vertical height than the maximum vertical dimension of the recesses, and substantially equal to the diameter of the lugs 29. It will further be observed that these lugs are eccentrically disposed -with respect to the rounded ends of the frame arms 28 so that when these arms are in their normal horizontal position as shown in Fig. 1 of the drawings, with their lower edges engaged with the arms 13 of the spider, the lugs 29 are disposed in the upper portions of the recesses 30 and out of alignment with the entrances 32 of said recesses. Thus it will be apparent that it is impossible for the frame arms 22 to become detached or disconnected from the arms 13. It will, therefore, be clear that such detachment can be effected only by first removing the seat 15. In assembling the parts before the seat is fixed upon the arms of the spider, the frame 27 is disposed in a vertical position as indicated at 27 in Fig. 4 of the drawings, and when the arms 28 are so disposed. the lugs 29 thereon may be moved through the entrances 32 and into the recesses 30. In this manner, the back supporting frame may be easily and quickly connected to the seat iron or spider for rocking or pivotal movement with respect thereto, after which the seat 15 is applied and lixed in position by the screws 16. It is also to be observed that the point of pivotal connection of this frame 27 with the arms 13 is substantially in transverse alignment with the axis of the supporting post 8.

The frame 27 is yieldingly urged upwardly to normally hold the arms 28 thereof in contact against t-he under side of the seat 15 by two coil springs 33 which surround the respective arms 13 of the seat iron or spider at opposite sides of the post 8. One end 34 of each of these springs is forwardly extended and engaged under a lug 35 projecting from an edge of the spider arm 11. The other end 36 of each spring is rearwardly extended. The intermediate portion of the frame 27 is formed on the inner side thereof with a horizontal web 37 and the under side of this web is provided in spaced relation to each of the arms 28, with a vertical flange 38. Thus seats are provided for the rearwardly projecting ends 36 of the springs against the under side of the web 27 between the flanges 38 and the arms 28 as clearly shown in Fi 2 of the drawings.

At this point, attention may be called to the fact that by reason of the construction just described, I am enabled to produce the seat supporting iron or spider on the upper end of the vertically adjustable post and the rocking frame 27 for the seat back each in the form of a single integral casting. Thus, I secure maximum strength and durability with relatively low manufacturing cost. Owing to the fact that the point of pivotal or rocking connection of the frame 27 with the seat spider and the axis of the spring coils 33 are substantially in line with each other, the desired responsive action of the springs 33 to pressure against the seat back is obtained while saidl springs are at the same time relieved of excessive strains.

The rearwardly projecting intermediate portion of the frame 27 has integrally cast therewith substantially at its Center a vertically disposed plate 39. This plate is adapted to be received in the longitudinal slot or bifurcation 41 formed in the lower end of the chair back 40. Said plate is provided in its lower portion with a horizontally extending slot 42 having a series of spaced notches 43 in its lower edge. These notches are adapted to receive a bolt 44 extending transversely through the lower end of the chair back, said bolt having a suitable nut 44 threaded on one end thereof. However, as will be hereinafter explained, this nut is not for the purpose of clamping the bifurcated end of the chair back against the opposite sides of the plate 39.

The chair back is further provided adjacent the upper end of the bifurcation 41 with a second transversely disposed pin or bolt 45 fixed therein and this pin is adapted to seat in a vertical notch or recess 46 formed in the upper and of the plate 39.

As will be clearly seen from reference to Fig. 1 of the drawings, when it is desired to adjust the angle of the chair back 40 with respect to the frame 37, it is only necessary to lift said back upwardly, thereby disengaging the bolt 44 from one of the notches 43 and also raising the pin 45 in the slot 46. The chair back is then swung either forwardly or rearwardly to the desired inclination and lowered to again seat the bolt 44 in another of the notches 43 while the pin 45 is seated in the lower end of the recess 46. Thus the chair back will be held at the required angle without necessitating any adjustment of the nut 45, when frequent adjustments of the chair back are to be made. On the other hand, if the chair back is to be permanently fixed in an adjusted position, it may be desirable to adjust the nut 45 and clamp the slotted or bifurcated end of the chair back against the plate 39 so as to prevent any possibility of accidental vertical movement of the chair back relative to the plate.

I have also herein shown a back rest 47 mounted upon the upper end of the chair back 40, and I preferably fix this back rest upon the opposite offset ends of a channeled metal plate 48, the channel therein providing longitudinal flanges 49 at the opposite edges of the plate which extend upon the respective sides of the chair back 40 and provide guides for the longitudinal movement of the back rest with respect to said chair back. This plate 48 is centrally provided with a longitudinally extending slot 50 therein which receives a squared section of a bolt 51 engaged through a suitable opening in the chair back 40. The rear threaded end of this bolt is provided with a clamping nut 52 of suitable form. It Will be evident, that by merely loosening this nut, the back rest 47 may be vertically adjusted to the desired position and the nut 52 then tightened against the rear side of the chair back to rigidly clamp the back rest in such position. It will be apparent that by the provision of the flanges 49 on the back rest plate extending over the side faces of the chair back 40, any turning or rotative movement of the back rest with respect to the chair back is etfectually prevented.

From vthe foregoing description considered in connection with the accompanying drawings, the construction, manner of operation and several advantages of my improved chair will be clearly understood. It will be seen that I have produced a chair particularly desirable for use by stenographers and typists wherein the chair back is so mounted and arranged and supported relative to the seat that it is yieldingly responsive to pressures thereon and may also be easily and quickly adjusted to any desired angular position so as to furnish the greatest degree of comfort to the person seated.in the chair. At the same time I have materially simplified the construction of the seat spider or iron and the back supporting frame so that chairs of this type may be produced and sold at a reasonable cost. I have herein referred to an embodiment of my present improvements which I have found to be entirely practical and satisfactory in use, but it will nevertheless be understood that the essential characteristics thereof might possibly be excured to the under side of a chair seat and having oppositely projecting arms to extend transversely under the seat, each of said arms having an ear on the upper side thereof provided with a pivot receiving recess closed at its upper side and having a lateral entrance at the front side of said ear, and a back supporting frame'consisting of a one piece integral casting provided with spaced arms each having a pivot lug movable through the entrance to one of said recesses when said frame is disposed in a vertical position, the ends of the frame arms and the pivot lugs being eccentric-ally related to each other and said arms preventing movement of the pivot lugs out of said recesses when the frame is moved to a horizontal rearwardly extending position.

2. In a chair, a spider adapted to be fixed to the chair seat having ears with pivot-receiving recesses closed at their upper sides and having entrances at the front sides of the ears, and a back-supporting frame having spaced arms with pivot lugs movable through the entrances of the recesses when said frame is disposed in a vertical position, the ends of the frame arms and the pivot lugs being eccentrically related to each other, and said arms preventing movement of the pivot lugs out of said recesses when the frame is moved to a horizontal rearwardly extending position.

3. In a chair, a spider adapted to be attached to a chair seat, said spider having pivot-receiving recesses closed at their upper sides and having entrances at the front sides, and a back-supporting frame having pivot lugs movable through the entrances into the recesses when said frame is lifted to a vertical position, the ends of the frame and the pivot lugs being ecoentrically related to each other, and said frame ends preventing movement of the pivot lugs out of said recesses when the frame is in the normal substantially horizont-al position.

In testimony that I claim the foregoing as my invention, I have signed my name hereto.

ANDREW J. CRAVEN. 

